1) First download SAP JCO Connector for your operating system from http://service.sap.com/connectors.
If you are using windows then make sure you download correct version of sapjco dll and jar.
For windows you need to place sapjco dll inside Windows\System32 directory

2) Next thing is configure sapjco3.jar
inside Lifeary portal.

Place this jar inside
[LIFERAY_TOMCAT]/lib/ext.

Liferay SAP
Integration

Following diagram will give you some
idea on integrating Liferay with SAP. [Image 1 Diagram]